Shoes for snowplows and the like



Nov. 16, 1965 w HEINZRQTH ETAL 3,217,431

SHOES FOR SNOWPLOWS AND THE LIKE Filed March 21, 1963 INVENTORS. EMIL J.HANK J Merl 6. Sceales 3/ AT'IoRNEY United States Patent Ofl Fice3,217,431 Patented Nov. 16, 1965 3,217,431 SHOES FOR SNOWPLOWS AND THELIKE William H. Heinzroth, Canton, and Emil J. Hank, Minerva, Ohio,assignors to Good Roads Machinery Corporation, Minerva, Ohio, acorporation of Ohio Filed Mar. 21, 1963, Ser. No. 266,878 1 Claim. (Cl.3742) This invention relates to shoes for supporting snowplows, graders,spreaders, and like devices a predetermined distance from the surface onwhich they are operating to decrease wear on the surface engaging partsof such devices.

In general, the invention is directed to a ground level flotation shoeassembly which resiliently supports a blade member, such as a moldboardof a snowplow, above the surface being operated upon. The shoes of suchassemblies which slide over the supporting surface regulate the heightof the blade or scraper from the ground, and under the presentinvention, each shoe assembly is of such a construction that the hingeline of rotation of the shoe is at or may be below the ground or surfacelevel. The weight of the assembly is carried on bearing means locatedwithin the housing of each sliding shoe and a pin which secures eachshoe to its respective shoe housing comes into play only when the entireshoe assembly is at a position Where the shoe is free of the ground oroperating surface. In previous constructions, the pin in service carriedthe entire weight of the shoe assembly :and the blade with which it wasemployed.

By locating the hinge line or pivot axis of the shoe at or below groundlevel, the effective moment around the hinge line is less than the casewhere the hinge line is above the ground level so that the constructionof the invention results in more uniform wear on shoes and consequentlonger life.

Other objects and advantages of the invention will appear in the coursesof the following description.

The drawing furnished herewith illustrates the best modes presentlycontemplated for carrying out the invention as hereinafter set forth.

In the drawing:

FIGURE 1 is a perspective view showing the shoe assembly of theinvention secured to a snowplow;

FIG. 2 is a side elevational view of the shoe assembly shown secured topart of a snow-plow assembly with parts broken away and sectioned;

FIG. 3 is a side elevational view looking at the right side of FIG. 2and with parts omitted;

FIG. 4 is a side elevational view showing the shoe pivoted in onedirection due to the irregularities of the surface over which the shoeis operating; and

FIG. 5 is a view similar to FIG. 4 and showing the shoe pivoted in theopposite direction.

The drawing, for the purposes of illustrating the use of the shoeassembly of the invention, shows a moldboard or blade 1 of a snowplow. Asemi-circular frame 2 is suitably secured to the rear of moldboard 1,and such frame is pivotally secured to the frame 3.which in turn ispivotally connected to the frame 4 on the prime mover 5. Thus, thesemi-circular frame 2 and moldboard 1 may be moved together in ahorizontal plane to horizontally locate the moldboard 1 in a number ofdifferent positions relative to its vertical axis. Means are employed tosecure frame 2 to frame 3 when the moldboard is in the position desiredbut need not be described as it has no bearing on this invention.

A trip spring assembly 6 is connected between the frame 2 and themoldboard 1 to permit the moldboard to override obstructions in the pathof travel with a spring, not shown, inside the trip spring cylinderefiecting return of the blade to normal service operation.

In order to lift the moldboard 1 and the accompanying parts so that theassembly may be transported free of a traveled surface, a hydrauliccylinder 7 is provided. The lower end of cylinder 7 is connected to apair of plates 8 which are secured to the frame 4 on the prime mover andthe upper end of the cylinder 7 is connected to the triangular shapedplates 9 which are pivoted to the upper ends of the vertical posts 10,the lower ends of such posts being secured to the frame 4. The outerends of triangular plates 9 are connected to the frame 2 by the chain 11so that when cylinder 7 is activated from the prime mover 5 throughhydraulic lines, not shown, the plates 9 are pivoted rearwardly on posts16 and lift the moldboard 1 and the assembled parts from the ground orother surface on which the unit is operating.

The moldboard 1 is normally provided at its leading edge with areplaceable cutting blade 12 and in most uses of the snowplow it isdesirable to raise the cutting blade 12 from the surface or ground beingoperated on so that the weight of the plow assembly is not carried bythe cutting blade with a consequent decrease in the useful life ofcutting blade 12. This is accomplished by providing casters, or shoesbehind the moldboard 1 on which the Weight of the assembly is taken andwhich provide a clearance between moldboard 1 and its cutting blade 12and the ground surface.

In the illustration of the shoe assembly of the invention in thedrawing, there is shown a resilient and adjustable connection of theshoe assembly to the snowplow unit previously described. Such assemblycomprises, in general, a shoe housing formed of the stem 13 and the footportion 14, a shoe 15 disposed below the foot portion 14, and connectedthereto by pin 16, and a housing 17 to receive'the stem 13 of the shoehousing.

The housing 17 is generally cylindrical and is secured to the verticallyspaced plate members 18 through which housing 17 vertically extends. Theplate members 18 are secured to the semi-circular frame 2 and form apart thereof. The top of housing 17 is closed by the cap nut 19 which isrigidly secured within housing 17. The lower end of the housing 17 isopen to slidably receive the stem 13 of the shoe housing.

Stem 13 and foot portion 14 of the shoe housing are hollow and may becast or of welded construction. Stem 13 is divided generally centrallyby partition 20 which has a central opening therethrough.

A bolt 21 extends upwardly through a vertical opening in partition 20and through a complementary vertical opening provided centrally in capnut 19. The opening in partition 20 is of a smooth bore while theopening in cap nut 19 is threaded. Bolt 21 at the neck portion isunthreaded but is threaded at the upper end complementary to the threadsin cap nut 19. The threaded section of bolt 21 extends upwardly frompartition 20 a substantial distance and the head 22 of bolt 21 abuts thebottom surface of partition 20.

In order to accomplish resilient support of the shoe housing andvertical adjustment thereof, the inside of the stem 13 of the shoehousing is provided with a coil spring 23 assembled around bolt 21 andwhich is confined between the partition 20 and the ball bearing unit 24assembled around bolt 21 above coil spring 23. The ball bearing unit 24is held in its predetermined position by the castellated nut 25 which isthreaded onto bolt 21 above bearing unit 24. The nut 25 is fixed in thedesired position by cotter pin 26. The assembly described permits thestem 13 to rotate within housing 17 with the coil spring 23 rotating onthe ball bearing unit 24. The position of the stem 13 and the footportion 14 of the shoe housing with respect to housing 17 is regulatedby rotating bolt 21 to the desired. position by means of handle 27.

The hollow foot portion 14 of the shoe housing is provided at the upperend with the circular flange 28 which may abut the lower end of housing17. In order to provide bearing surfaces for the shoe 15, the bearingblocks or inserts 29 extend horizontally within the respective ends ofthe foot portion 14. The shoe is received within the foot portion 14 ofthe shoe housing and the upper surface 30 of shoe 15 rests against thebearing blocks 29 in service and slides over such blocks.

The shoe 15 is of a solid construction and in order to provide for readymovement of shoe 15 on bearing blocks 29 the upper surface 30 of theshoe is of a semicircular shape, and the bearing blocks 29 are formedwith their bearing surfaces complementary to the upper surface 30 of theshoe 15.

The lower portion 31 of shoe 15 is of a generally rectangular shape andis flat on the bottom to readily slide over a surface. The outer ends 32of the shoe 15 extend upwardly angularly outwardly to give the shoe thegeneral appearance and action of a sled runner and thereby provide formore efiicient movement of the shoe 15 over the surfaces on which it isoperating.

In order to provide a loose connection between the foot portion 14 ofthe shoe housing and the shoe 15, and yet permit relative movementbetween shoe 15 and pin 16, the shoe 15 generally centrally thereof andadjacent the upper edge, has an elongated slot 33 which is disposed inalignment with an aperture 34 extending horizontally through the footportion 14 of the shoe housing.

The elongated extent of slot 33 lies generally in a plane correspondingto the semi-circular plane in which the surface 30 of shoe 15 extends.The walls of the foot portion 14 are enlarged downwardly below aperture34 as at 35 to reinforce the aperture.

Pin 16 extends through slot 33 and aperture 34 with the head of the pinabutting against one wall of the foot portion 14 and the fastening means36 for securing the pin 16 in place abutting the opposite wall.

Pin 16 is disposed loosely within slot 33 with a clearance thus beingprovided between pin 16 and slot 33 in the shoe 15, as shown in anexaggerated manner in FIG. 2 of the drawing. The clearance describedpositively insures that the Weight of the supported snowplow does notbear on the pin 16, but rather, in service only bears directly on theshoe 15. Thus, the only function of pin 16 is to hold the shoe 15 andfoot portion 14 of the shoe housing together when the entire shoeassembly is free of the ground or other operating surface.

FIGS. 4 and 5 illustrate the action of the shoe 15 when passing over anuneven surface 37 tending to tilt the shoe. Thus, in FIG. 5, the shoe 15has tilted upwardly at the forward end. However, the shoe cannot turnover because it is of a sufficient width, as shown in FIG. 3, to engagethe walls of the foot portion 14, as shown in FIG. 5 of the shoehousing. been tilted in the opposite direction.

The hinge line, or pivot axis 38 of rotation of shoe 15, is located ator below the ground or surface level in that shoe 15 rotates on the axis38 which is described by the center of the circle of which bearinginserts 29 are a part. As the diameter of the circle of which bearing InFIG. 4, the shoe 15 has 4 inserts 29 are a part is increased beyond thatshown in FIG. 2, the hinge line or pivot axis 38 of shoe 15 will movebelow the ground level. Thus, when the shoe, for example, as in FIG. 4,engages an uneven surface, the low hinge line prevents the shoe fromtending to tilt or tip over with consequent decrease of wear on theengaging end of the shoe. Instead, the shoe, due to the decrease of theeffective moment around the hinge line tends to level off and movedownwardly toward the obstruction with a consequent pivoting of the shoeand movement of the slot therein forwardly with respect to the pin 16.An opposite action is reflected in the shoe in FIG. 5 where an unevensurface is being passed over by the rear portion of the shoe.

Various modes of carrying out the invention are contemplated as beingwithin the scope of the following claim particularly pointing out anddistinctly claiming the subject matter which is regarded as theinvention.

I claim:

A flotation shoe assembly having a housing adapted to be secured toportable apparatus and support said apparatus on a surface with thehinge line of the assembly being at or below ground level whichcomprises:

(a) a solid sliding shoe having a generally flat bottom merging intoupwardly inclined end portions with a semi-circular upper surface andhaving a single generally centrally located elongate-d slot in the upperportion thereof extending in a plane complementary to the upper surfaceof the shoe,

(b) a shoe housing having a cylindrical stem projecting centrallyupwardly therefrom into said housing and secured thereto and a footportion with the foot portion having an aperture extending therein inline with the slot in said shoe,

to) circumferentially spaced bearing inserts provided within the bottomside of the foot portion to receive the shoe and support the shoehousing directly on the shoe, with the bottom surface of the bearinginserts being of a shape conforming to the upper surface of the shoe sothat the shoe is adapted to move freely over said bearing inserts, and

(d) a pin extending through the aperture in the foot portion of the shoehousing and said pin having a diameter less than the width of the slotsuch that the pin extends loosely through the slot in the upper portionof the shoe to hold the shoe and shoe housing together when the shoeassembly is raised from the supporting surface and without affecting thebearing of the shoe housing directly on said shoe when the shoe is inservice on the supporting surface.

References Cited by the Examiner UNITED STATES PATENTS 435,666 9/1890Rempio 280-26 572,847 12/1896 Wesle 28026 727,472 5/1903 Snell 280-26933,510 9/1909 Wesle 28026 2,460,348 2/1949 Henry 37148 X 2,778,126 1/1957 Shannon 37-42 BENJAMIN HERSH, Primary Examiner.

